Mechanical means for extending the operating radius of a log loading boom



March 24, 1959 Flled Nov. 25, 1957 March 24, 1959 A. R. WIRKKALA 2,873,946

MECHANICAL MEANS FOR EXTENDING THE OPERATING RADIUS oF A Los LOADING Boom Filed Nov. 25, 1957 i 2 Sheets-Sheet 2 INVENTOR. ALBERT R. WIRKKALA Unitecl` States Patent() MECHANICAL MEANS FOR EXTENDING THE OPERATING RADIUS oF A LOG LOADING vBOOM Albert R. Wirkkala, Naselle, Wash.

Application November 25, 1957, Serial No. 698,446

` 1 Claim. (Cl. 212-7) This invention relates to powered article loading, lifting, and moving machines vof those variousv kinds equipped with an arch, boom, or arm from the end` of While the present invention is not to be restricted to any exact mode of use, or to be confined to any particular type of loading or moving operation, it has reference more particularly to certain improvements in log handling and loading machines of those types or kinds which employ a boom, and wherein a load carrying cable is adapted to be paid out from and drawn in by a cable winding drum, and which cable passes over a fairleader at the end of the boom, and is equipped at its outer end with tongs, or other suitable means, ywhereby a holding connection can be quickly made with the logs for picking them up for loading, piling, or'otherwise moving them.

Heretofore, in the use of log handling devices or machines of the above stated character employing a boom, the radius of operation about the machine at any setting has been limited approximately to the reach or extent of the boom and when it was desired to pick up or haul in a log that was located much beyond the extent or reach of the boom, the cable and tongs had to be carried out from the boom to the log for its attachment thereto.

Incidentally, this usually requires that the cable be manually pulled out from the cable winding drum andy this, as a general rule, is a diiiicult task. vThe same is true regardless of the particular `job being done, the articles being handled `or the type or kind ofl device being used at the end of the cable for making the connection with the article to be moved.

In view of the limited working radius of the machine, asV above explained, the principal object of this invention is to provide a powered mechanism especially designed to be used in conjunction with a load lifting or loading boom or arm, whereby the load lifting `cable andthe load attaching device used at its end, whether it be tongs, hook, or a means of other form, may be pushed or carried out well beyond the end-of the boom or arm to a position ifor its ready connection with an object or article that is to be moved, thus to increase the effective radius of operation of the'machine accordingly.

It is a further objectofV the present invention to provide a cable push-out or extension means of the above character .that can 4be mounted in various ways upon or within the extended arm or boom of the machine, and which push-out mechanism can be easilyxcontrolled by the Amachine operator without causing any slowdown from from the usual and heretofore used mode of operation.- t i yMore specifically stated, the objects and advantages of the presentinvention reside in the provision of an extendable meanswhich may be mounted upon or within the boom, and operable `'for the above stated purpose of carrying the loading cable `well out beyond the boom ice 2 zend; which meansV is light in..weight and may be easily and quickly operatedl between extended and retracted positions by various typesvof powered means. 4

Still further objects and advantages of the present invention reside in the detailskof construction and combination of parts employedvvtherein, and in the mode of operation as will hereinafter be fully described.

In accomplishing the abovel mentioned and other objects of the invention, I-have provided the improved details of construction, the preferred forms of which are illustrated in the accompanying drawings, wherein:

Fig. 1 is a side view of a present day log loading machine having its boom equipped with a power operated, telescopically extendable and retractable rod or arm for carrying the outer end portion of the load lifting cable and the tongs a distancewell beyondV the boom end.

Fig. 2 is an enlarged top view partly in section, of the telescopic, extendable cable` push-,out cylinder embodied by the present invention as shown in Fig. l, including a diagrammatic showing Yof 'the air control system.

Fig. 3 is a view showing in side elevation, an extendable cable carrying arm as equipped with cable belt for effecting its extension and retraction.

Fig. 4 is an enlarged cross-sectional view, taken on line 4-4 in Fig. 3.k

Fig. 5 is a side view with parts in section, of still another alternative form of cable extending means embodied by the invention. y. v

Fig. 6 is a cross-section taken on line 6-6 in Fig. 5. v It is not the intent thatA the present invention be conined in use to any particular type or make of machine, Or to machines having any particular kind of boom, arm, arch or load carrier. In the present drawings, the machine shown is intended to be one that is typical of those now in general use for log loading operations. The boom also is of typical form but .its detailsl of construction might be varied to considerable extent without departing from the invention. Furthermore, while I have .shown the log lifting or hauling cable as being equipped at its end with tongs, it might, alternatively, be equipped with any one of a variety of kinds of hooks or attachments, depending upon the particular work to be done. Furthermore, the present invention is applicable to machines known as high arches; to wreckers as used on rail cars or on trucks; to drag line operations with tractors as used for log skidding and to various analogous machines and operations. i

Referring more in detail to the drawings:

In Fig. 1, 10 designates a logging machine to which the present improvement, in one of its various forms, has been applied. This machine. is of the conventional shovel type, in that it comprises a turntable 11 mounted on a base structure 12 that is equipped with crawler tracks 13. l

Mounted on the turntable is an engine, here designated by reference numeral 14,. which is operable through various clutches and controls, not herein shown, for the selective driving of cable winding drums 16. .The turntable 11 also supports annangledboom 17; this being hinged or pivoted at itsinner end, as at 18, for its raising and lowering as may be effected by the usual or any suitable cable connection such as, for example, that designated at 19. At its outer endthe boom 17 is equipped with a suitable fairleader 20 through .which a logging cable 21 is reeved. This cable is wound fo'nand extended from an engine driven drum .16., At its outer end 4the cable 21 is equipped with a pair of tongs 22 of a kind appropriate for the work at hand. p

In using a machine of this type not equipped with the present invention, for log loading,- the boom is first swung to a position directed toward or overthe log thatv is to i be picked up. Then.the=tong mangrasps .the/tongs' .lengthwise thereof. `shown in Fig. 2, is a piston 26, to which is fixed a piston and pulls or carries them to the log and applies them thereto at the proper location. The tong cable 21 is then wound in on drum 16, causing the log to be lifted and heeled against the boom in themanner well known in -the industry. With the log thus supported, the drum is held and the boom raised and the log swung thereby to a position over a truck or car onto which it was to be loaded; the cable 21 is then paid out from the drum and the log placed in -proper position on the truck. The tongs are then released from the log and the boom swung back to position for the pick up of another log.

It is a present day practice of some loggers in this work as above stated, to swing the boom back to the load pick-up position with sufficient rapidity that the vtongs will be thrown centrifugally somewhat beyond the `end of the boom. However, this practice anticipates or requires that some sort of power device, for example,

such as those known as slack pullers, be used to draw out the cable from the cable winding drum. The use of the push-out means herein shown, and embodying the present invention, eliminates theundesirable and dangerlair cylinder 25 that is rigidly and fixedly mounted by any suitable means in the outer endportion in the boom Contained in the cylinder, as best rod 27 that extends forwardly from the cylinder and ythrough a guide and supporting bearing 28 at the outer end of the boom. At its extreme end, the rod 27 is For the operation of the air cylinder 2S, air conduits 30 and 31 lead to its forward and rearward ends respectively, from an air control valve 32 that is located in a -position readily accessible to the machine operator. As 4indicated schematically in Fig. 2, the control valve 32 has a pipe connection 33 with a source of air under pressure, designated at 35. By proper manipulation of the valve 32 by the machine operator, air can be applied to the inner end of the air cylinder as exhausted from yits outer end, thus to drive the piston outwardly. This application of air extends the piston rod 27 and carries the cable 21 as passed through loop 29, outwardly from the boom end to a corresponding distance, thus to increase the effective working'radius of the boom accordingly. After the tongs 22, as carried at the cable end, have been lowered and applied to a log, the rod 27 is retracted by an application of air under pressure through valve 32 to the outer end of the cylinder 25 and exhausted from its inner end. `With the piston rod retracted, the pull applied on the cable 21 for lifting the log, or for dragging it back to position for heeling against the boom, will be sustained by the fairleader 20 and not by the piston rod. While I have indicated the push out device as being controlled by air under pressure, it is possible also to use a hydraulic medium in lieu of air under pressure.

As an alternative form of cable push-out device, a cable operated extensionmeans as illustrated in Fig. 3, might be satisfactorily employed. In this particular showing, an elongated arm, or beam 40, is telescopically contained in a tubular housing 41 that is fixed in the boom at the location occupied by the air cylinder in Fig. l. The housing 41, in this instance is of rectangular crosssection, as notedin Fig. 4,.and the beam or arm 40 that is telescopically rcontained therein is equipped at itsV inner end with-guide-,ro1lers..43 ywhich. travel on the upper and lower walls of .the housing, The housing is equipped at its outer endwith roller 44 which support and guide the arm y,or beam 40 for extension and retraction. This arm also passes slidably through a guide bearing 28 at the end of the boom and at its end carries a cable guide loop 40' through which cable 21 depends from the fairleader.

The arm 40, in this instance, is shown to be operated by means of cables 46-46' that are connected to a bracket 47 that is fixed to the inner end of the arm 40 to extend downwardly therefrom through a slot 49 formed lengthwise of the housing. As here shown, the slot 49 is in the underside wall of the housing. The cable 46 extends forwardly from the bracket 47, about a sheave 49 at the forward end of the housing, and then extends rearwardly, The cable 46 extends rearwardly from the bracket. The two cables, 46 and 46', are adapted to be simultaneously wound in opposite directions onto and from a drum, such as that at 16x in Fig. l, under control of the operator, thus to effect either the extending of the arm to carry the cable and tongs outwardly, or to effect retraction of the arm. ln this arrangement, the drum 16x may be located in the boom structure and operated by an electric motor supplied with current from a battery or generator operated by the engine 14.

Instead of using tne above described air cylinder means of Fig. l or the cable operated means of Fig. 3, for the extension or retraction of the cable push-out arm, yet another alternative mechanism as shown in Fig. 5, may be employed. In this form of device, I employ an arm 40 and a housing 41 in the same manner as shown in Fig. 3, but instead of employing cables for its extension and retraction, the arm 40 is equipped along its top edge with a toothed rack 50' with which a relatively large gear 51, mounted on a drive shaft 52, is meshed.

.Shaft 52 is rotatably supported in a bearing 53 carried by housing 41 and is equipped with a relatively small belt Wheel 54, about which one end of a continuous belt 55 operates. The other end of the belt extends about a supporting wheel 56. This belt is adapted to be driven in opposite directions by its connection, as at 60, with the outer end of the piston rod 61 of an air cylinder 62 which is fixedly mounted in the boom. It will be understood that extension and retraction of the piston rod drives the cable belt and thus rotates shaft 52 and gear 51 to cause the arm 40 to be extended or retracted and its movement as thus effected will be to a substantially greater extent than the piston rod travel by reason of the difference in the diameters of gear 51 and belt wheel 54.

By use of any of the various means above described, it will be possible to cause the tong cable, when retracted, to be engaged at a point adjacent its connection with the tongs, and carried out to a position well beyond the boom end thus to, in effect, increase the length of the boom accordingly. This extending of the boom eliminates much of the time consuming work of the tong man and speeds up the logging operation to substantial extent.

The present invention is applicable to practically all forms of log loaders, and to various other machines such as high arch loggers Where an extended arm or frame carries a drop cable or line for load pick up purposes. It can be applied in a like manner to railway car wreckers, to trucks, and to drag line operations which are carried out by use of a hoorn or crane.

, What Il claim as new is:

A log loading machine of the character described, said machine comprising a loading. boom hingedly mounted at one end, a fairleader block mounted on the other end of the boom on the top surface thereof and extending beyond the outer end thereof, a cable winding drum, a cable wound on and extending from said drum above the boom and through said fairleader block to depend therefrom, log holding means secured to the free end of said cable, a guide fixed to said boom lengthwise thereof. a

cable carrying rod slidably mounted in said guide for endwise movement from a retracted position along said boom to an extended position beyond the end thereof, means operable for extending and retracting said rod, means on the outer end of said rod for engaging the log holding means and thereby causing the cable to be extended incident to the extension of the rod, said means on the end of the rod permitting free passage of the cable therethrough so that no force is exerted upon the rod when the cable is lifting a log.

References Cited in the le of this patent UNITED STATES PATENTS 

